Rust Sea
From Teletraan I: The Transformers Wiki
The Rust Sea is an area of unstable planetary matter and molecular flux located along Cybertron's equator, stretching from Tyrex to Polyhex.[1] Or in simple terms, it's exactly what its name implies. It's a sea, but it's not full of water.[2]
The Hydrax Plateau rises out of the center of it. Cybertron's primary spaceport is located here, where planetary visitors must check in first.
